Goodwill (Carrying Amount of Goodwill by Reportable Segment) (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($)
Goodwill [Line Items]
Goodwill, Gross Beginning Balance	$ 1,412,806
Accumulated impairment losses Beginning Balance	(34,178)
Goodwill, Beginning Balance	1,378,628
Acquisitions	(7,597)
Foreign currency translation	681
Goodwill, Gross Ending Balance	1,405,890
Accumulated impairment losses Ending Balance	(34,178)
Goodwill, Ending Balance	1,371,712
Title Insurance and Services
Goodwill [Line Items]
Goodwill, Gross Beginning Balance	1,366,041
Accumulated impairment losses Beginning Balance	0
Goodwill, Beginning Balance	1,366,041
Acquisitions	(7,597)
Foreign currency translation	681
Goodwill, Gross Ending Balance	1,359,125
Accumulated impairment losses Ending Balance	0
Goodwill, Ending Balance	1,359,125
Specialty Insurance
Goodwill [Line Items]
Goodwill, Gross Beginning Balance	46,765
Accumulated impairment losses Beginning Balance	(34,178)
Goodwill, Beginning Balance	12,587
Acquisitions	0
Foreign currency translation	0
Goodwill, Gross Ending Balance	46,765
Accumulated impairment losses Ending Balance	(34,178)
Goodwill, Ending Balance	$ 12,587